Selective reverse water gas shift: group 1a alkali metal doping of a metal-containing partially reduced metal (iv) oxide

Abstract

A catalyst and method of reducing carbon dioxide to carbon monoxide via a reverse water gas shift reaction. The catalyst comprises Group 1A alkali metal doping of a metal-containing partially reduced metal (IV) oxide. Such catalyst selectively hydrogenates carbon dioxide to carbon monoxide at relatively low temperatures with a selectivity that reduces or avoids carbon dioxide conversion into hydrocarbons such as methane.

What is claimed is: 
     
         1 . A catalyst for performing a reverse water gas shift (RWGS) reaction comprising a partially reduced metal (IV) oxide active support of one or more of a ZrO 2 , TiO 2 , HfO 2 , CeO 2 , ThO 2  or MnO 2  that contains a metal of one or more of a Pd, Pt, Ir, Cu, Ag or Au, wherein the catalyst is doped with a Group 1A alkali metal of one or more of a Na, Li, K, Rb or Cs. 
     
     
         2 . The catalyst of  claim 1  wherein said partially reduced metal (IV) oxide active support of one or more of a ZrO 2 , TiO 2 , HfO 2 , CeO 2 , ThO 2  or MnO 2  contains said metal of one or more of a Pd, Pt, Ir, Cu, Ag or Au at a level of 0.5 wt. % to 10.0 wt. %. 
     
     
         3 . The catalyst of  claim 1  wherein said partially reduced metal (IV) oxide active support of one or more of a ZrO 2 , TiO 2 , HfO 2 , CeO 2 , ThO 2  or MnO 2  contains said metal of one or more of a Pd, Pt, Ir, Cu, Ag or Au at a level of 0.5 wt. % to 5.0 wt. %. 
     
     
         4 . The catalyst of  claim 1  wherein said partially reduced metal (IV) oxide active support comprises ZrO 2  and contains Pt. 
     
     
         5 . The catalyst of  claim 4  wherein said Pt is present at a level of 0.5% (wt.) to 5.0% (wt.). 
     
     
         6 . The catalyst of  claim 1  wherein the Group 1A alkali metal is present in said catalyst at a level of 0.1% (wt.) to 10.0% (wt.). 
     
     
         7 . The catalyst of  claim 1  wherein the Group 1A alkali metal is present in said catalyst at a level of 0.1% (wt.) to 10.0% (wt.) 
     
     
         8 . The catalyst of  claim 1  wherein said Group 1A alkali metal comprises Na and is present in said catalyst at a level of 0.1% (wt.) to 5.0% (wt.). 
     
     
         9 . The catalyst of  claim 5  wherein said Group 1A alkali metal comprises Na and is present in said catalyst at a level of 0.1% (wt.) to 5.0% (wt.). 
     
     
         10 . The catalyst of  claim 1  wherein said partially reduced metal (IV) dioxide active support comprises a partially reduced ZrO 2 . 
     
     
         11 . The catalyst of  claim 10  wherein said partially reduced ZrO 2  has a surface that contains surface Zr +3  sites and/or surface —OH groups. 
     
     
         12 . A method for catalyzing a reverse water gas shift reaction comprising:
 a. providing a catalyst comprising a partially reduced metal (IV) oxide active support of one or more of a ZrO 2 , TiO 2 , HfO 2 , CeO 2 , ThO 2  or MnO 2  that contains a metal of one or more of a Pd, Pt, Ir, Cu, Ag or Au, wherein the catalyst is doped with a Group 1A alkali metal of one or more of a Na, Li, K, Rb or Cs;   b. supplying the catalyst with a flow of carbon dioxide and hydrogen gas;   c. heating the catalyst to a temperature in the range of 200° C. to 500° C. and a pressure of 1 bar to 40 bar; and   d. recovering carbon monoxide.   
     
     
         13 . The method of  claim 12  wherein greater than or equal to 96.0% of the supplied carbon dioxide is converted to carbon monoxide. 
     
     
         14 . The method of  claim 12  comprising heating to a temperature in the range of 200° C. to 400° C. and a pressure of 1 bar to 20 bar wherein greater than or equal to 96% of the carbon dioxide is converted to carbon monoxide. 
     
     
         15 . The method of  claim 12  wherein said partially reduced metal (IV) oxide active support of one or more of a ZrO 2 , TiO 2 , HfO 2 , CeO 2 , ThO 2  or MnO 2  contains said metal of one or more of a Pd, Pt, Ir, Cu, Ag or Au at a level of 0.5 wt. % to 10.0 wt. %. 
     
     
         16 . The method of  claim 12  wherein said partially reduced metal (IV) oxide active support of one or more of a ZrO 2 , TiO 2 , HfO 2 , CeO 2 , ThO 2  or MnO 2  contains said metal of one or more of a Pd, Pt, Ir, Cu, Ag or Au at a level of 0.5 wt. % to 5.0 wt. %. 
     
     
         17 . The method of  claim 12  wherein said partially reduced metal (IV) oxide active support comprises ZrO 2  and contains Pt. 
     
     
         18 . The method of  claim 17  wherein said Pt is present at a level of 0.5% (wt.) to 5.0% (wt.). 
     
     
         19 . The method of  claim 12  wherein the Group 1A alkali metal of one or more of a Na, Li, K, Rb or Cs is present in said catalyst at a level of 0.1% (wt.) to 10.0% (wt.). 
     
     
         20 . The method of  claim 12  wherein the Group 1A alkali metal of one or more of a Na, Li, K, Rb or Cs is present in said catalyst at a level of 0.1% (wt.) to 5.0% (wt.). 
     
     
         21 . The method of  claim 12  wherein the Group 1A alkali metal comprises Na and is present in said catalyst at a level of 0.1% (wt.) to 5.0% (wt.). 
     
     
         22 . The method of  claim 18  wherein the Group 1A alkali metal comprises Na and is present in said catalyst at a level of 0.1% (wt.) to 5.0% (wt.). 
     
     
         23 . The method of  claim 17  wherein said ZrO 2  has a surface that contains surface Zr +3  sites and/or surface —OH groups. 
     
     
         24 . A method for catalyzing a reverse water gas shift reaction comprising:
 a. providing a catalyst comprising a partially reduced zirconium (IV) oxide active support that contains Pt at a level of 0.5 wt. % to 10.0 wt. % wherein the catalyst is doped with Na at a level of 0.1 wt. % to 10.0 wt. %;   b. supplying the catalyst with a flow of carbon dioxide and hydrogen gas;   c. heating the catalyst to a temperature in the range of 200° C. to 500° C. and a pressure of 1 bar to 40 bar; and   d. recovering carbon monoxide wherein greater than or equal to 96.0% of the carbon dioxide is converted to carbon monoxide.   
     
     
         25 . The method of  claim 24  wherein said partially reduced zirconium (IV) oxide active support has a surface that contains surface Zr +3  sites and/or —OH groups. 
     
     
         26 . The method of  claim 25  wherein greater than or equal to 96.0% of the supplied carbon dioxide is converted to carbon monoxide.